Reduced loading time, resolution

Reduced loading time of maps, loading time has been roughly divided by 2, I now pre-calculate lights and other stuffs for maps before releasing. It increases level file size, but reduces loading time.

Concatenated all textures, it reduces a bit loading time, and decreases apk size

The resolution slider in the option is back, I have corrected the bug I had with dynamic resolution changes, and the controls are zoomed so that they always have the same size on screen (only the level size and sprite change)

The hardware back button is better handled now, it will pop menu when in-game, pressing it twice will really quit the game (a message is displayed when pressing once)